Accurate Potential Energy Curve for B2. Ab Initio Elucidation of the Experimentally Elusive Ground State Rotation-Vibration Spectrum
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- 作者：Laimutis Bytautas ; Nikita Matsunaga ; Gustavo E. Scuseria ; Klaus Ruedenberg
- 刊名：The Journal of Physical Chemistry A
- 出版年：2012
- 出版时间：February 23, 2012
- 年：2012
- 卷：116
- 期：7
- 页码：1717-1729
- 全文大小：997K
- 年卷期：v.116,no.7(February 23, 2012)
- ISSN：1520-5215
文摘
The electron-deficient diatomic boron molecule has long puzzled scientists. As yet, the complete set of bound vibrational energy levels is far from being known, experimentally as well as theoretically. In the present ab initio study, all rotational鈥搗ibrational levels of the X 3危g鈥?/sup> ground state are determined up to the dissociation limit with near-spectroscopic accuracy (<10 cm鈥?). Two complete sets of bound vibrational levels for the 11B2 and 11B-10B isotopomers, containing 38 and 37 levels, respectively, are reported. The results are based on a highly accurate potential energy curve, which also includes relativistic effects. The calculated set of all vibrational levels of the 11B2 isotopomer is compared with the few results derived from experiment [Bredohl, H., Dubois, I., and Nzohabonayo, P. J. Mol. Spectrosc. 1982, 93, 281; Bredohl, H., Dubois, I., and Melen, F. J. Mol. Spectrosc. 1987, 121, 128]. Theory agrees with experiment within 4.5 cm鈥? on average for the four vibrational level spacings that are so far known empirically. In addition, the present theoretical analysis suggests, however, that the transitions from higher electronic states to the ground state vibrational levels v = 12鈥?5 deserve to be reanalyzed. Whereas previous experimental investigators considered them to originate from the v鈥?= 0 vibrational level of the upper state (2)3危u鈥?/sup>, the present results make it likely that these transitions originate from a different upper state, namely the v鈥?= 16 or the v鈥?= 17 vibrational level of the (1)3危u鈥?/sup> state. The ground state dissociation energy D0 is predicted to be 23164 cm鈥?.